One vertex per element, one color per generator, with an edge from x to x·s.
(9,10,16,15)(11,20,14,17)(12,19,13,18)(21,23,22,24)(25,26,32,34)(27,35,30,33)(28,31,29,39)(36,40,37,38)(1,2)(3,8)(4,6)(5,7)(9,11,16,14)(10,17,15,20)(12,22,13,21)(18,24,19,23)(25,27,32,30)(26,33,34,35)(28,36,29,37)(31,38,39,40)(1,3,5,6)(2,4,7,8)(9,12,16,13)(10,18,15,19)(11,21,14,22)(17,23,20,24)(25,28,32,29)(26,31,34,39)(27,36,30,37)(33,38,35,40)(1,2)(3,4)(5,7)(6,8)(9,13,16,12)(10,19,15,18)(11,22,14,21)(17,24,20,23)(25,29,32,28)(26,31,34,39)(27,37,30,36)(33,38,35,40)(1,2)(3,4)(5,7)(6,8)(9,14,16,11)(10,20,15,17)(12,22,13,21)(18,24,19,23)(25,30,32,27)(26,33,34,35)(28,37,29,36)(31,38,39,40)(1,4)(2,6)(3,7)(5,8)(9,15,16,10)(11,20,14,17)(12,19,13,18)(21,24,22,23)(25,31)(26,29)(27,38)(28,34)(30,40)(32,39)(33,37)(35,36)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.